IBM Power 595, Технический обзор и введение

Страница: 127 / 188

Chapter 3. Virtualization
115
systems allow you to have an off-site, disaster recovery machine at a lower entry price in
comparison to a standard 595 server.
The CBU offering includes:
4 processors that are permanently activated and can be used for any workload
28 or 60 standby processors available for testing or for use in the event of disaster
1800 (4/32-core) or 3600 (4/64-core) On/Off CoD processor days
CBU processor resources can be turned on at any time for testing or in the event of a disaster
by using the On/Off CoD activation procedure. If you have used the initial allotment of
processor days (1800 or 3600), additional processor capacity can be purchased using On/Off
CoD activation prices. Standby processors cannot be permanently activated.
Minimum and maximum configuration requirements for memory and I/O are the same as for
the standard 595 server offerings. For further information about CBU, visit:
http://www.ibm.com/systems/power/hardware/cbu
3.4 POWER Hypervisor
Combined with features designed into the POWER6 processors, the POWER Hypervisor
delivers functions that enable other system technologies, including logical partitioning,
virtualized processors, IEEE VLAN compatible virtual switch, virtual SCSI adapters, shared
and virtual consoles. The POWER Hypervisor is a basic component of the system’s firmware
and offers the following functions:
Provides an abstraction between the physical hardware resources and the logical
partitions that use them.
Enforces partition integrity by providing a security layer between logical partitions.
Controls the dispatch of virtual processors to physical processors (see 3.5.2, “Shared
processor pool partitions” on page 117).
Saves and restores all processor state information during a logical processor context
switch.
Controls hardware I/O interrupt management facilities for logical partitions.
Provides virtual LAN channels between logical partitions that help to reduce the need for
physical Ethernet adapters for inter-partition communication.
Monitors the service processor and will perform a reset/reload if it detects the loss of the
service processor, notifying the operating system if the problem is not corrected.
The POWER Hypervisor is always active, regardless of the system configuration (LPAR or full
system partition). It requires memory to support the resource assignment to the logical
partitions on the server. The amount of memory required by the POWER Hypervisor firmware
varies according to several factors. The following factors influence the POWER Hypervisor
memory requirements:
Number of logical partitions
Number of physical and virtual I/O devices used by the logical partitions
Maximum memory values given to the logical partitions
The minimum amount of physical memory to create a partition is the size of the system’s
Logical Memory Block (LMB). The default LMB size varies according to the amount of
memory configured for the system as shown in Table 3-6 on page 116.